In an electronic device testing apparatus called a handler, a large number of electronic devices held on a tray are conveyed into the electronic device testing apparatus, and the respective electronic devices are brought to electronically contact a test head for conducting a test by an electronic device testing apparatus body (hereinafter, also referred to as a tester). When the test is finished, the electronic devices are taken out from the test head and reloaded to trays in accordance with the test results so as to be classified to categories of good ones and defective ones, etc.
In conventional electronic device testing apparatuses, there is a type wherein a tray for holding pre-test electronic devices or post-tested electronic devices (hereinafter, also referred to as a customer tray) differs from a tray conveyed by circulating inside the electronic device testing apparatus (hereinafter, also referred to as a test tray). In an electronic device testing apparatus of this kind, electronic devices are reloaded between the customer tray and the test tray before and after the test, and the electronic devices are pressed against a test head in a state of being carried on the test tray in a test step for conducting a test by bringing the electronic devices to contact the test head.
On the other hand, there is known a type wherein electronic devices held on a customer tray are applied with a thermal stress by using a heat plate, etc., then, some of them are picked up by suction heads at a time, conveyed to a test head, and brought to electronically contact. In a test step of an electronic device testing apparatus of this kind, electronic devices are pressed against the test head in a state of being picked up by the suction heads.
When being pressed, a large number of contact portions are provided to the test head (Normally, the number of test positions capable of measuring at a time, that is, the simultaneously measured number is limited to 2n, that is 32 or 64, per one electronic device testing apparatus. Note that “n” is a natural number.), and by conducting tests on a large number of electronic devices at a time, tests with high throughput are conducted.
Conventionally, when conducting tests on electronic devices, the test has been conducted in a final step of production steps of the electronic devices, so that a test has been conducted on completed electronic devices after steps of molding and wire bonding, etc. are finished.
However, when judged to be defective by the test after finishing the production steps, steps up to the completion after becoming a state of being ready for the test may be wasted, so that it is preferable that the test is conducted when it became to be in the state of being ready for the test and the defectives are taken away at this stage.
In the production steps of electronic devices, as shown in FIG. 16(a) to FIG. 16(h), due to limitation of the nature of the electronic device 20, the electronic devices 20 to be tested are loaded on an electronic device conveying medium of strip formats 10, etc. for preventing the electronic devices 20 from parting for conveying within and between respective steps. But the electronic device conveying medium 10 loads any number of electronic devices 20 and has any arrangement of the electronic devices 20. Note that FIG. 16(a) shows the electronic device conveying medium 10 loaded with electronic devices 20 by the number of 96 in arrangement of 4 rows by 24 columns, FIG. 16(b) shows the electronic device conveying medium 10 loaded with electronic devices 20 by the number of 60 in arrangement of 3 rows by 20 columns, FIG. 16(c) shows the electronic device conveying medium 10 loaded with electronic devices 20 by the number of 48 in arrangement of 3 rows by 16 columns, FIG. 16(d) shows the electronic device conveying medium 10 loaded with electronic devices 20 by the number of 36 in arrangement of 3 rows by 12 columns, FIG. 16(e) shows the electronic device conveying medium 10 loaded with electronic devices 20 by the number of 32 in arrangement of 2 rows by 16 columns, FIG. 16(f) shows the electronic device conveying medium 10 loaded with electronic devices 20 by the number of 24 in arrangement of 2 rows by 12 columns, FIG. 16(g) shows the electronic device conveying medium 10 loaded with electronic devices 20 by the number of 32 in arrangement of 4 rows by 8 columns, and FIG. 16(h) shows the electronic device conveying medium 10 loaded with electronic devices 20 by the number of 36 in arrangement of 2 rows by 18 columns.
Accordingly, as explained above, to conduct a test on an electronic device 20 in a state it became ready for the test before reaching the final step, the test has to be conducted while the electronic devices 20 are in an arrangement loaded on the electronic device conveying medium 10, furthermore, the arrangement of the electronic devices 20 loaded on the electronic device conveying medium 10 has to be kept to be conveyed to the next step.
Also, contact portions 110a of a test head of the conventional electronic device testing apparatus composed only one contact group 110 composed of the contact portions 110a by the number measured at a time limited in the electronic device testing apparatus as shown in FIG. 17 and FIG. 18.
FIG. 17 shows one contact group 110 configured that the number of the contact portions 110a is limited to 32, and FIG. 18 shows one contact group 110 configured that the number of the contact portions 110a is limited to 64.
Therefore, for example, when securing test positions with the simultaneously measured number of 32 for the electronic devices 20 to be tested loaded on the electronic device conveying medium 10 (rectangular shaped electronic devices arranged in 3 rows by 16 columns in the case of this example) shown in FIG. 19, it is possible to secure test positions of 32 at the first test (Post-tested electronic devices 21 in FIG. 19 show all of 32 black squares in the figure.), while only remaining 16 test positions can be secured (Pre-test electronic devices 22 in FIG. 19 show all of 16 white squares in the figure.) at the second test. Thus, only half the number of the 32 contact portions is used in the second test, so that there was a disadvantage that the test efficiency declines.
Also, when always securing the simultaneously measured number of 32 regularly on the electronic device conveying medium 10 having an arbitrary arrangement of the electronic devices 20, it is considered, for example, one contact group 110 composed of 32 contact portions 110a are divided to 32 contact groups, and 32 electronic device conveying media 10 are conveyed at a time to conduct a test on electronic devices to be tested 20 loaded on the electronic device conveying media 10 at a time. In this case, there is a disadvantage that the apparatus becomes huge and complicated, so that it is more preferable to secure the simultaneously measured number with as few electronic device conveying media 10 as possible.
The present invention was made in consideration of the above problems of the prior art and has as an object thereof to provide an electronic device testing apparatus capable of conducting a test with a high test efficiency on electronic devices 20 on an electronic device conveying media 10 by any number and in an arrangement thereof.